Computerized dynamic posturography is used to measure the balance. Subjects had to maintain their COG stable in 3 consecutive series of 20s duration for each of the 6 conditions in the test. In the first 3 conditions, the platform remained fixed. Condition 1 was conducted with open eyes, condition 2 with closed eyes and condition 3 with a mobile visual environment referenced to postural oscillations. Conditions 4, 5 and 6 repeated the visual conditions of the first 3 tests and added platform movement referenced to the anteroposterior oscillation of the subject, with the ankle-foot angle remaining constant, thus annulling proprioceptive sensory input.